Part a:
In this study, we have only a reference value of 16% (the proportion of people that can wiggle ears) and a population of 342 millionaires whose results we want to compare with this reference value. Since there is a relativelly high number of millionaries that were surveyed, we should use the z-test for a population proportion.
Part b:
It p is the sample proportion, the null hypothesis, in this case, is given by:
Therefore, the alternative hypothesis is given by:
Part c:
According to the data, the z-score is given by:
Part d:
According to the normal table, the p-value related to z-score given by:
0.638
Part e:
Therefore, we can check that this p-value is > a
Part f:
Based on this, we should ACCEPT the null hypothesis.
Part g:
Thus, the final conclusion is that the data suggest the population proportion is not significantly different from 16% at a = 0.01, so there is statistially significant evidence to conclude that the population proportion of millionaries who can wiggle their ears is equal to 16%.